The present invention relates to a semiconductor device that includes a semiconductor element for high frequency applications and an overcurrent-protecting function in a hollow airtight package and a method of manufacturing the same.
An example of the semiconductor device employing the hollow package in the conventional art is shown in FIG. 9. This electronic parts comprise a base substrate 1 formed of ceramic, etc., a lead 2 for external connection, and a cap 3 formed similarly of ceramic. A semiconductor chip 5 is adhered onto a surface of an element mounting portion 4 of the lead 2, then the semiconductor chip 5 and the lead 2 are connected via bonding wires 6, and then the semiconductor chip 5 is sealed in an airtight space 7 constructed by the cap 3 (for example, Patent Application Publication Hei 10-173117).
Such parts are manufactured via steps of preparing the lead 2 in the form of a lead frame, then bonding the semiconductor chip 5 to the lead frame via die bonding or wire bonding, then mounting the base substrate 1 on a bottom surface of the lead frame, then mounting the cap 3 on the base substrate 1 to put the leads 2 between them, and then cutting/shaping the leads 2.
However, in the semiconductor device in the conventional art, there is the subject that, since the base substrate 1 and the cap 3 are mounted on the lead frame every element, the manufacturing steps become complicated and are not suited for the mass production.
Also, there is the problem that, since the semiconductor chip 5 is sealed in the airtight space 7 that is constructed by the cap 3 made of ceramic, etc., the adhesion state cannot be checked by the visual inspection and thus it is difficult to remove the semiconductor device in which the adhesion failure is caused.
A semiconductor device of the present invention has been made in view of the above circumstances, and comprises a supporting substrate made of insulating material, a conductive pattern provided on a surface of the supporting substrate, and external connecting terminals provided on a back surface and connected electrically to the conductive pattern, a circuit element provided on the conductive pattern, a glass plate adhered to cover the circuit element and to form an airtight hollow portion between the supporting substrate and the glass plate, and an adhesive resin applied to an overall adhered surface of the glass plate.
Preferably, the semiconductor device of the present invention has such a feature that, since the light-shielding adhesive resin is applied to the overall adhesive surface of the glass plate that is used to house the circuit element in the airtight hollow space, the state of the adhered portion can be checked by the visual inspection and also the direct incidence of the light onto the circuit element can be prevented, whereby the change in the characteristic of the circuit element can be avoided in structure.
In order to overcome the above problems, the semiconductor device manufacturing method of the present invention is characterized by comprising a step of preparing a supporting substrate in which a conductive pattern having a large number of mounting portions is provided and external connecting terminals are provided on a back surface, a step of adhering the circuit element onto the mounting portions respectively, a step of applying an adhesive resin to an overall adhesive surface of a glass plate that covers the circuit element and forms an airtight hollow portion between the supporting substrate and the glass plate every mounting portion, a step of adhering the supporting substrate and the glass plate to form the airtight hollow portion every mounting portion, and a step of separating the supporting substrate every mounting portion by dicing adhered portions between the supporting substrate and the glass plate.
Preferably, the semiconductor device manufacturing method of the present invention has such a feature that, since the light-shielding adhesive resin is previously applied to the overall adhesive surface of the glass plate that forms the airtight hollow space in the step of forming the airtight hollow space, a plurality of semiconductor elements can be formed at a time, whereby the manufacturing steps can be simplified and the mass production can be carried out.